Managing Grassland Ecosystems: Teacher Notes

Transcription

1 Managing Grassland Ecosystems: Teacher Notes Elspeth Swan Managing grassland ecosystems Eastern Barred Bandicoot Objectives After completing this activity, students will be able to: Identify factors contributing to the degradation of grasslands and suggest management strategies. Investigate research obtained by Australian scientists about the impact of humans on grasslands. Target audience Level 7

2 1 Duration Two 50-minute sessions Materials Whiteboard and whiteboard markers Teacher s computer connected to an overhead projector, access to Google Earth, electronic images of grasslands across Victoria (Current Victorian grasslands and Pre 1750 Victorian grasslands) and the BWVP Flora and Fauna Field Guide Class set of computers: access to the BWVP Managing Grasslands learning object and the BWVP Flora and Fauna Field Guide Student workbook Pencil Activity Victoria was settled in 1835 and Europeans quickly exploited grasslands. Today, less then one per cent of the original grasslands remain in small remnant patches. Since European settlement, grasslands have been managed in different ways, which has changed the landscape. The following is a list of threats to grasslands: Introduction of exotic plant species: Introduced species compete with native species and may also change the physical and chemical structure of grasslands. Introduction of feral pests: Many pests have been introduced, such as the Red Fox and the domestic cat which prey on or compete with native fauna resulting in the extinction of several species. Others like the European Rabbit and Common Hare compete with native species and cause damage to the landscape. Over-grazing by stock: The soil is compacted by hard-footed stock, palatable grassland species are depleted and grazing tolerant species are prolific. Fertiliser application: Fertilisers increase soil nutrients and can be applied to pasture species to encourage growth. Most native species compete best under low nutrient levels and are usually out-competed when fertiliser is applied. Rock removal and ploughing: Recent technologies are enabling farmers to access farming land that was once deemed too rocky. When the soil and rock layer is disturbed this destroys and removes fauna habitat, disturbs soil invertebrate communities and removes most of the native vegetation.

3 2 Urbanisation: The expansion of urbanisation onto rural land has resulted in the loss of native grasslands. Changed water use: Dams and weirs have been constructed along waterways. These structures deprive wetlands and streams of their natural flows, which affects the movements of aquatic species. Altered fire regimes: The frequency of fire has reduced since European settlement. Frequent use of fire by Aboriginal people maintained high diversity of species and controlled the regeneration of some woody species. The key to grassland management is to identify the threats to grasslands and protect the sites through the development of management strategies. The following activities allow students to learn how to return a degraded grassland site to a high quality grassland, and how Aboriginal people managed grasslands in a sustainable manner. Introduction Begin this lesson by engaging students in a brainstorming session about the threats to grasslands and how to manage them. Explain that grasslands were once very common across western Victoria, from Melbourne to the South Australian border. Since European settlement, grasslands have been managed in different ways, which has resulted in only small patches of grasslands remaining. Discuss how land management has changed since European settlement and how grasslands could be improved. Prompt students to consider farming practices and how they have changed the landscape. Reintroduce terms such as flora, fauna and introduced animal and plants. Consider these prompts to keep the discussion lively and record the results on the board (answers have been provided). What is flora and fauna? Flora refers to plants and fauna refers to animals. What does the word indigenous mean? Indigenous means originating or occurring naturally in an area or environment. List native plants and animals that live in grasslands. Ground covers, herbs, grasses, shrubs and a few trees are common in grasslands. The animals that live in grasslands include reptiles such as lizards, amphibians such as frogs, mammals such as bandicoots, birds such as cockatoos and invertebrates such as spiders. For a list of plants and animals found in Western Volcanic Plains grasslands, look at the BWVP Flora and Fauna Field Guide. What is an introduced species? An introduced species is also known as exotic, non-native or non-indigenous. It is a species living outside its native distribution range.

4 3 Show students the images displaying the extent of grasslands throughout Victoria, pre European settlement (1750) and recently (2010). Ask students to explain the differences in the images. In the 1750 image the natural temperate grassland (shaded yellow) is dominant throughout the Western Volcanic Plains. The current extent (2010) of natural temperate grasslands is virtually extinct. Only 0.1% remains. What has caused the decline in grasslands over the last 260 years? The First Fleet arrived in Sydney in 1788 from England. The aim was to establish the first British Colony in Australia. When British people colonised Australia they used land practices they were familiar with; the land was cleared for development and exotic plants and animals were introduced. Aboriginal people used the land in a sustainable manner, therefore the new land practices placed a strain on ecosystems. The following are a list of threats to grasslands, which have caused a decline in distribution: introduced species, introduced pests, over-grazing by stock, fertiliser application, rock removal and ploughing, urbanisation, changed water use and altered fire regimes. Ask students to complete question 1 in their workbook. : Grassland management Appropriate management strategies are needed to improve degraded grassland sites. This activity enables students to answer the following questions: How can grasslands be managed? What can be done to improve grasslands? Firstly, students need to explore the meaning of management? Pose the question to students and write answers on the board. Write the following grassland threats on the board and ask students to consider possible management strategies to improve a grassland site. Grassland management involves undertaking activities that preserve and improve a grassland site. This includes activities that manage the land, plants and animals. Introduction of exotic plants: Weed cover can be variable depending on the time of year, climate, disturbance history and site conditions, and weeds may require all year round attention. Weeds should be strategically removed prior to flowering. Introduction of feral animals: Eradicate all feral animals. Over-grazing by stock: Prevent trampling and excessive grazing pressure. Fertiliser application: Promote native grasslands on the property, which will save applying fertiliser. When fertiliser use is required, ensure that it is not used in or near a grassland. Rock removal or ploughing: Avoid activities that result in removing rocks or disturbing the soil. Urbanisation: Avoid activities that result in excessive soil disturbance or plant removal. Changed water use: Avoid altering the natural flow of waterways.

5 4 Lack of fire: Get advice from your local Department of Environment and Primary Industries (DEPI) to develop an appropriate fire regime for your property. Ensure any controlled burning is appropriately managed. Ask students to complete question 2 in their workbook. Secondly, students will explore their school and consider what management strategies could be implemented to improve their school landscape. Go to Google Earth ( and search for your school s location. Project this image on an overhead projector for students to examine. Pose the following questions: Can you see vegetated areas or cleared areas? Can you see bitumen or concrete? Are there any watercourses nearby? Where are there areas that provide habitat for animals such as birds, reptiles, amphibians and insects? Are there wildlife corridors that link your school to existing habitat nearby such as parklands, wetlands or rivers? How could your school area be improved e.g. replanting of native species and fencing off areas? Managing grassland ecosystems learning object Thirdly, students will simulate the implementation of grassland management strategies by completing an interactive online Managing Grassland Ecosystems learning object. The aim of this activity is to return a grassland site, which has become degraded yet still contains some indigenous grassland plants and possibly fauna, to a high quality grassland suitable for the reintroduction of populations of animals. Open the Managing Grassland Ecosystems learning object and follow the instructions to complete the activity. Students will record results from the activity and answer questions Activity 2: Study an endangered species Eastern Barred Bandicoot The aim of the second activity is to illustrate conservation in action and show how a range of agencies, groups and individuals are working together to conserve a threatened species. Students will study the Eastern Barred Bandicoot and discover how changes in the environment have impacted on their survival leading the species to become endangered. This activity shows how Action Plans and Recovery Teams help to provide an overview of the threats facing the Eastern Barred Bandicoot. and the specific actions that need to be undertaken to conserve them. Prior to studying the Eastern Barred Bandicoot, pose the following questions to the students. What does endangered mean? An organism that is endangered is at risk of being extinct.

6 5 Do you know of any endangered animals? Students may talk about many plants and animals and may include non-australian animals including the Giant Panda, Red Wolf, Southern Bluefin Tuna and the Siberian Tiger. What has caused these animals to be endangered? There are many reasons why an animal becomes endangered. Some causes include habitat loss, pollution, competition from other organisms, over exploitation and introduction of introduced species. List the organisations and groups that study and aim to conserve threatened organisms. Organisations include the Department of Environment and Primary Industries (DEPI), Zoos Victoria, Parks Victoria, Mt Rothwell Biodiversity Interpretation Centre, universities, botanic gardens, local Councils, Friends groups, Landcare groups, landowners and individuals. What is the Victorian legislation that aims to conserve threatened organisms? The Flora and Fauna Guarantee Act 1988 provides a framework for the legal protection of Victoria s native species. The aim of the Act is to ensure that our native flora and fauna survive and flourish. Explain to students that they will study the Eastern Barred Bandicoot. Students will open the BWVP Flora and Fauna Field Guide and find the Eastern Barred Bandicoot (Perameles gunnii) in the group Mammal Marsupial. Students will complete questions and investigate the habitat requirements, diet and the factors that have led to the bandicoot becoming Extinct in the Wild (previously critically endangered). Students will go to the Conservation Status tab and select the FFG Action Statement to explore what is being done to manage the species. You may like to project the Eastern Barred Bandicoot s page from the BWVP Flora and Fauna Field Guide on an overhead projector to show students where to find the information. Also it might be useful to show students the FFG Action Statement and explain how to read it. Conclusion Conclude the session by engaging students in a brainstorming session about how to manage grasslands. Here are some examples to keep the discussion lively. How have grasslands been threatened? What has caused the decline in the size the distribution of grasslands in Victoria? How does changing the physical conditions of grasslands impact on animals like the Eastern Barred Bandicoot? What can be done to improve the numbers of the Eastern Barred Bandicoot? Students should then complete the conclusion questions in their workbook.

7 6 Managing grassland ecosystems Prior to European settlement grasslands extended over the Western Volcanic Plains in Victoria. Grasslands across the Western Volcanic Plains are now listed as Critically Endangered. 1. Grasslands are now fragmented, which means grasslands are broken up into smaller remnants. What is the impact of fragmentation? When fragmentation occurs, the movement of plants and animals decreases and as a result biodiversity declines. These areas will become susceptible to reduced genetic diversity. 2. There were once a variety of herbivores and carnivores roaming the grasslands across the Western Volcanic Plains. Some of these animals are now extinct in the wild. Many factors have contributed to their decline in number and in some cases the extinction of a species. On the left is a list of threats to grasslands. Find and match the threat with the negative impact on the environment. Introduction of feral animals Soil is compacted and native grasses are eaten by cattle Introduction of exotic plants Habitat is removed when rocks are disturbed and removed Over-grazing of native plants by cattle The development of buildings, houses and roads has resulted in the loss of native plants and animals Fertiliser is applied to the grasses Exotic plants compete with native plants Rocks are removed Dams and weirs have been constructed along some rivers and streams, which have altered the natural flow Urbanisation and development Introduced animals compete with native animals and damage the landscape Changed water use A reduced amount of fire reduces diversity of plants in grasslands Lack of fire Fertilisers may kill native plants

8 3. List two ways grasslands can be managed. i. Student answers will vary ii. Student answers will vary 4. 7 Why are grassland ecosystems threatened? Grasslands are generally found on flat land, which is suitable for settlement and agriculture. 5. How is an agricultural crop field different from a native grassland? Agricultural crops usually contain a single plant species. In order to increase productivity, fertiliser and chemicals can be used. A native grassland is much more diverse. It has many species of plants and animals that interact with one another. Follow the instructions and complete the computer activity. This activity simulates how to manage a degraded grassland site. 6. Once you have completed the activity list your suggestions for managing the site: i. Weed Management: (Best response) Strategic weed removal prior to plants flowering. ii. Site Access: (Best response) Construct a predator-proof exclusion fence, which is actively monitored and maintained. iii. Feral Animal Management: (Best response) Eradicate all feral animals including foxes, feral cats, rabbits and European Hares. iv. Vegetation Restoration: (Best response) Prepare the site and then directly sow indigenous seeds, plant tube stock or subterranean plant organs. v. Fauna Reintroductions: (Best response) Reintroduce indigenous fauna species with active monitoring. 7. What was your overall assessment? Student responses will vary. 8. Why are weeds a problem in grasslands? Weeds often produce a large number of seeds. This means many new weeds can be created. Weeds compete with native plants, using soil moisture and space where native plants could otherwise grow. If there are fewer native plants there is less food and shelter for native animals. 9. Why is a predator- proof fence so effective? A predator-proof fence is one that is specifically designed to exclude animals such as foxes, feral cats, rabbits and dogs.

9 8 10. Circle the feral animals from the following list: Foxes Rabbits Bandicoots Hares Kangaroos Feral cats Feral dogs Cockatoos 11. What impact do feral animals have on grasslands? Feral animals compete with native animals for food and shelter. They can affect which native plants grow in a grassland. 12. Why is it important to manage weeds, grazing and vehicles when reintroducing native plants? If weeds, grazing and vehicles are not managed well at the site, the reintroduced plants may be overgrown by weeds, eaten, trampled or crushed. 13. What is the best order to implement the management strategies? Weed management weed removal 2 Site access install predator-proof fence 1 Feral animal management feral animal removal 3 Vegetation restoration replanting 4 Fauna reintroductions reintroduce native animals Why is it important to reintroduce native animals last? Before a native species is reintroduced to a site, the site needs to be safe and have suitable habitat for that species. 15. If land owners wanted to improve their grassland sites, would the cost of any management strategies deter them from implementing new management strategies? Explain. The construction of a predator-proof fence is an extremely costly exercise and may not be feasible for most land owners. Fauna reintroductions and relocations are also extremely expensive, and success is not certain. The purchase of plants for revegetation and eradication of feral animals is also a costly exercise. 16. Which of the management strategies are the most accessible for land owners? The strategic removal of weeds in a time consuming exercise however is a method most land owners could undertake.

10 9 Study an endangered animal You will investigate an endangered animal. Open the BWVP Flora and Fauna Field Guide and find the Eastern Barred Bandicoot (Group: Mammal - Marsupial). Investigate the information found on the Field Guide and open the FFG Action Statement (click on Conservation Status to find the link and look for clues as to why the organism is endangered). Complete the table below. Common name Eastern Barred Bandicoot Scientific name Perameles gunnii Diet Herbivore Characteristics (circle answer) Carnivore Small mammal with white stripes on rear of back, short white tail and long nose. Omnivore They eat small invertebrates including worms, beetles, crickets and caterpillars plus plant bulbs, fruits and fungi. Habitat Tall, dense native grasslands (circle answers) Montane (mountainous country) Modified habitats with shelter Conservation status DEPI Advisory List Extinct in the Wild Reasons for conservation status Habitat loss or modification (circle answers) Habitat fragmentation Grassy woodlands FFG Act Listed as threatened Inappropriate planting of trees EPBC Act Endangered Introduced predators Rubbish dumping Open-shrub land Weeds Small population size Native animal predation Management issues Manage wild population at Hamilton Habitat management Write Management and Recovery Plans Establish captive breeding Re-introduce the Eastern Barred Bandicoot into fenced enclosures Research monitor population, analyse habitat etc. Community involvement

11 Describe the Eastern Barred Bandicoot s habitat, in particular the role of tussock grasses. Eastern Barred Bandicoots require a habitat of tall, dense native grasslands and grassy woodlands. Eastern Barred Bandicoots require dense grasses to hide from predators. 18. Is predation by introduced animals a threat for the Eastern Barred Bandicoot? Predation by introduced animals is a threatening process for the Eastern Barred Bandicoot. 19. The Eastern Barred Bandicoot was once widespread on the grassland plains of western Victoria. By the 1980s studies found the bandicoot had been reduced to a few populations around Hamilton. One colony lived at the Hamilton Tip. Suggest how the Eastern Barred Bandicoot was able to survive in the Hamilton Tip. The tip site contained patches of native grassland and the car wrecks provided additional shelter from foxes and cats. 20. Zoos Victoria along with other organisations conduct captive breeding programs. i. What is captive breeding? Captive breeding is the process of breeding animals in human controlled environments, in settings like the Zoo. Captive breeding programs help to improve the population of threatened animals and may save a species from extinction. ii. In what ways does captive breeding help the conservation of Eastern Barred Bandicoots in the wild? Captive breeding enables breeding bandicoots for the wild, genetic research and other studies. 21. There are a few sites throughout Victoria that are being used to re- introduce the Eastern Barred Bandicoot. What features should the re- introduction sites have to make them suitable for the release of captive bred Eastern Barred Bandicoots? Re-introduction sites must have suitable habitat, which is dense, tall native grasslands and grassy woodlands, and control of predators, such as foxes, cats and rabbits. 22. Explain the benefit of controlling foxes, cats and rabbits within a site where the Eastern Barred Bandicoot has been re- introduced. What are some ways that foxes, cats and rabbits could be controlled? Foxes, cats and rabbits could be excluded from a grassland site by erecting a predator proof fence. If introduced animals are inside an exclusion fence a baiting or shooting program should be implemented.

12 11 Read the following passage: A developer is requesting permission to purchase land for a new shopping centre development. The land is located on the outskirts of town in a native grassland area. The shopping centre would be constructed on land where an Eastern Barred Bandicoot population would be threatened. The shopping centre will create jobs during the development stage and once in operation. 23. List the pros and cons: Should the developer be granted permission to go ahead with the project? Can you think of any alternatives or options that could be considered? Students should list pros and cons for the argument. Conclusion 24. When managing a grassland ecosystem, what needs to occur to ensure the reintroduction of native animals to the site? To ensure the reintroduction of native animals to a degraded site the following must occur: weeds must be removed; a predator proof exclusion fence must be installed; feral animals must be eradicated; and indigenous seeds or plants sown and grown. 25. What are the main contributing factors as to why the Eastern Barred Bandicoot is extinct in the wild? Habitat loss or modification and predation by introduced species are the main threats to the Eastern Barred Bandicoot. 26. What management strategies are implemented to enable Eastern Barred Bandicoots to live in the semi- wild? The management strategies that could be implemented include the construction of a predator proof fence, baiting or shooting programs to control foxes, cats and rabbits, removal of weeds and replanting native grasses, shrubs and trees. 27. Explain how adverse changes in the environment affect organisms. Give one example referring to the Eastern Barred Bandicoot. Students should choose one of the threats of the Eastern Barred Bandicoot and explain the impact.